# Molecular Design of Benzothiadiazole-Fused Tetrathiafulvalene Derivatives for OFET Gas Sensors: A Computational Study

## TL;DR

This study uses computational methods to design new organic semiconductors that could be used in gas sensors with high performance and sensitivity.

## Contribution

The paper introduces new benzothiadiazole-fused tetrathiafulvalene derivatives designed for dual-function OFET gas sensors.

## Key findings

- Designed TTF derivatives show high charge transport properties suitable for organic semiconductors.
- The derivatives are predicted to be sensitive to gases like NH3, H2S, and SO2.
- Frontier molecular orbitals and reorganization energy analysis supports their sensing potential.

## Abstract

Theoretical calculations (PBE0/6-311G(d,p)) predict the designed promising organic semiconductors with high mobilities.

TTF derivatives exhibit sensitivity to gases (NH3, H2S, SO2), suggesting potential for dual-function organic field-effect transistors (OFETs) with integrated sensing capabilities.

Due to their unique advantages—such as small size, easy integration, flexible wearability, low power consumption, high sensitivity, and material designability—organic field-effect transistor (OFET) gas sensors have significant application potential in fields such as environmental detection, smart healthcare, robotics, and artificial intelligence. Benzothiadiazole fused tetrathiafulvalenes (TTF) are promising organic semiconductor candidates due to their abundant S atoms and planar π-π conjugation skeletons. We designed a series of derivatives by side-chain modification, and conducted systematic computations on TTF derivatives, including reported and newly designed materials, to analyze how geometric factors affect the charge transport properties of materials at the PBE0/6-311G(d,p) level. The frontier molecular orbitals (FMOs) and reorganization energy indicate that the designed derivatives are promising candidates for organic semiconductor sensing materials. Furthermore, theoretical calculations reveal that the designed TTF derivatives are sensitive to gases like NH3, H2S, and SO2, indicating organic field-effect transistors (OFETs) with gas-sensing functions.